The basics Lumin's Workshop Foam Clay starts out as a foamy putty like clay that stretches and blends back into itself beautifully. The benefits The cured foam clay pieces do not need to be heat sealed but should be primed before painting. Foam clay pieces take 48 hours to cure before painting, cutting or sanding. The uses Perfect for adding details to your foam armor, the foam clay dries into a high density foam which can be cut, sanded, heat formed and glued.  The bottom line When you need to add details to your foam armour, Lumin's Workshop Foam Clay is the perfect tool.